Question about using a thermal camera for intermittent faults

I was chasing a weird autopilot trim fault on a King Air 200 for two days. The logbook just said 'autopilot unreliable,' and I was swapping boxes and checking connectors. My boss, an old guy who's been at our shop in Tulsa for 30 years, walked by and said, 'Did you look at it with the FLIR?' I hadn't. I borrowed the shop's thermal camera and ran the system. One of the servo motors was about 15 degrees hotter than the other after just five minutes of bench testing. The insulation on a wire bundle inside had rubbed through, causing a short that only showed up under load. I felt like an idiot for not starting there. Has anyone else had a simple tool tip them off to a problem they were overcomplicating?

2 comments

2 Comments

nancy2751mo ago

That "felt like an idiot" part is so real. It's amazing how a problem can seem impossible until you look at it in a different way. I've spent hours on something only to have a simple trick show the answer in seconds. Those old guys have seen everything, so their simple suggestions always hit hard. A thermal camera is such a smart first step for electrical stuff now that you mention it.

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nathan_patel1mo ago

Right? @nancy275, that simple trick thing is the worst and best feeling. I keep a cheap thermal camera in my bag now just for that first look, it cuts so much time. You stare at a board forever, then boom, one hot component tells the whole story. Those old guys never had the tech, so their fixes seem like magic, but we get to cheat a little.